Cancell my suscription

Hi,
I recently go for the standard plan in order to have multiple users for my domain. I started with free plan but when i have to add another domain i have an error so i upgraded to standard plan for add another domain. BUT when i wanted to add another user the system said that i must order another licence for another user. SO, i decided to cancel my suscription and return to the free plan but i want to be refounded :(.

Please help me, thank you very much.